Thread retainer for sewing machines



Aug. 31, 1926.

, lnvenTor. Arnold Krohn WM Warm Aflys.

Patented Aug. 31, 1926.

- UNITED STATES issuesrr ca.

Parent ARNOLD KROHN, OF EAST WEYMOUTH, MASSACHUSETTS, AS SIGNOR TO REECEBUTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A. CORPORATION OFMAINE.

. THREAD RETAINER FOR SEWING MACHINES.

Application filed March 2, 1926. Serial No. 91,721.

This invention relates to two-thread sewing machines of the type inwhich the underthread manipulating mechanism includes a needle carriedby an oscillatory needle carrier and one of the objects of the inventionis to provide a novel device for preventing the under needle frombecoming de-threaded either when the sewing machine is brought to restand the thread is trimmed or severed, or during the formation of thefirst stitch when the sewing operation is begun.

The invention includes a thread-holding member which is associated withthe oscillatory needle carrier for the under needle and is arranged togrip the thread lightly at a point between thethread-guiding eye that iscarried by the needle-carrier and the eye of the needle, the grip on thethread being sufiicient to prevent the thread from being accidentallywithdrawn from the eye otthe needle but not being suflicient to increasematerially the tension on the thread during the sewing operation.

In order to give an understanding of the invention I have illustrated inthe drawings a selected embodiment thereof which will now be describedafter which the novel features will be pointed out in the appendedclaims.

Fig. 1 is a view of the turret of a buttonhole sewing machine carryingthe underthread manipulating mechanism and having my improvementsapplied thereto;

Fig. 2 is an enlarged view of the needle carrier with the improvedthread-gripping device thereof;

Fig. 3 is a side View of the needle carrier;

Fig. 4 is a section on the line 4l4, Fig. 2;

Fig. 5 is a section on the line 55, Fig. 2.

The invention is herein illustrated as it might be applied to a sewingmachine of the general type shown in Patent No. 1,188,- 9-12, dated June27th, 1916 but as the invention relates simply to the device associatedwith the under-thread manipulating mechanism for preventing thede-threading of the under needle I have not thought it necessary toillustrate the complete sewing machine herein.

In a sewing machine of the type illustrated in said patent theunderthread manipulating mechanism, which includes an oscillatory curvedneedle, is carried by a turret which is situated beneath the work and isrotatably mounted on the frame of the sewing machine. Such turret isindicated generally at 1. The under needle which constitutes part of themeans for manipulating the under thread is indicated at 2, this being acurved needle which is mounted in an oscillatory needle carrier 3. Thisneedle carrier is formed with a depending arm 4 carried by a horizontalrock shaft 5 which is journalled in the turret and which is oscillatedby any suitable or usual means thereby to cause the needle to moveupwardly through the throat plate 6 and through the work and then to beretracted into the position shown in Fig.1. a

7 indicates the usual oscillatory looper which co-operates with theupper and under needle to assist in 'concatenating the up per and underthreads. The 'under thread which is indicated at 8 is led in usual waythrough a hollow spindle 9 of the turret and thence out through theopening 10 and through the tension 11 and thence through guide eyes 12and 13 carried by a thread-guiding arm 1% and thence through a guide eye15 carried by the arm 4- of the needle carrier and thence throughanother guide eye 16 formed in the needle carrier, said thread extendingfrom-the guide eye 16 to the eyes 17 18 of the under needle;

The parts thus far described are or may be all as substantially shown inPatents No. 1,188,942 or No. 1,535,899, April 28th, 1925.

and as the operation ofa sewing machine of 7 this type is well known tothose skilled in the art it will not be necessary to further illustratethese parts.

In the operation of sewing machines of this type it sometimes happensthat the under needle 2 will become de-threaded either when the machineis brought to rest and the threads are trimmed by some suitablethread-trimming mechanism or when the machine is first started, and toprevent this occurrence I have provided herein a novel device whichapplies a light tension to the thread between the guide eye 16 on theneedle carrier and the needle eye 17. this tension being sufficient toprevent the thread from being pulled backwardly through the needle eyethus causing the de-threading of the needle.

The device herein shown for this purpose is in the form of a finger 19which is yieldingly held against the thread 8 as it emerges from theguide eye 16. This finger forms part of a resilient arm 20 whichoverlies the outer face 21 of the needle carrier, said finger 19extending across the endof the needle carrier as shown best in Figs. 2and 5. The end of the needle carrier is illustrated as provided with arecess 22 in which the finger 19 is received sothat said finger does notextend beyond the end of the needle carrier. The resiliency of the arm20 lightly presses the finger 19 against the wall 23 of th groove 22.The under thread 8 passes behind the finger 19 andis thus lightlypressed against the wall by the arm, said arm applying sufiicienttension to the thread to prevent it being pulled back through the eye ofthe needle 2.

The device can be conveniently madefrom a piece of resilientwi're whichis bent into the shape shown to present the resilient arm 20 and thefinger 19. Said device is shown as being retained in place by means of ascrew 24, the end of the arm 20 passing under the head of the screw. andbeing clamped against the face of the needle carrier by said screw head.rier is preferably formed with a groove 25 to receive the arm. The endof the finger 19 extendsvslightly beyond the inner face 26 ofthe needlecarrier and is bent downwardly as shown at 27, the purpose of whichconstruction is to facilitate the placing of the thread under the finger19 when the machine is threaded up. The threading up of the machinevinvolves the insertion of the thread throughthe guide eyes'12. 13, 15and 16 in succession. As the thread is inserted through the eye 16 itwill emerge from the eye on the outside of the finger 19 since thelatter is yieldingly pressed against the wall 28 bythe arm 20 and toplace the thread back of the finger 19 and in a position to be grippedthereby the operator passes the thread. around the beak or nose Theneedle car- I WVhile' I have illustrated herein a selected embodiment ofthe invention I do not wish to be limited to the constructional detailsshown. I I

I clain1- I I I 1. In a sewingmachine, the combination with anoscillatory needle carrier having a thread-guiding eye through which theunder thread passes, of a needle carriedby said carrier and also havingan eye through which Y said thread passes, and'means for applying alight tension to said thread between the eye of theneedle carrier andthe eye of'the needle. I

2. In a sewing machine, the combination with an oscillatory needlecarrier having a thread-guiding eye through which the under threadpasses, of a needle carried by said carrierand alsohaving an eye throughwhich said thread-passes, and a finger bearing on the thread between theeye of the needle carrier and the eye of the needle. I

8. In a sewing machine, the combination with a needle carrier, ofa'needle extending from the end thereof, said needle carrier having athread-guiding eye extending therethrough and terminating at said endadjacent the base of the needle, and a finger yieldingly held againstthe thread at the delivery end of said eye. I I

In testimony whereof, I. have signed my name to this specification.

ARNOLD KROHN.

